Two Yankees players could face assault charges for brawling with a Fenway Park groundskeeper who went into the Bomber bullpen and rooted for the Red Sox, Boston police said yesterday.

The incident capped a violence-marred playoff game that included the throwing to the ground of Yankee bench coach Don Zimmer, 72, by Boston pitcher Pedro Martinez during a bench-clearing melee.

The Yankees won the game, 4-3, taking a 2-1 lead in the best-of-seven series for the American League pennant.

Police officials wouldn’t name the players, but they were identified by Red Sox spokesman Charles Steinberg as relief pitcher Jeff Nelson and outfielder Karim Garcia.

“Summonses may be issued, but we’re looking for more detailed information and are looking to interview all involved parties,” said Boston police spokeswoman Mariellen Burns.

Garcia suffered cuts to his hand leaping over a fence and the groundskeeper, Paul Williams, was left with cleat marks on his back and his arm.

Steinberg said he may have been kicked in the mouth.

“He was standing in our bullpen waving the rally flag,” Nelson said. “I told him, ‘If you’re rooting for the Red Sox, why don’t you go in their bullpen.’ He jumped in my face and tried to take a swing at me.”

Tempers were already heated after the bench-clearing incident in the fourth inning.

“We’ve upgraded from a battle to a war,” Boston manager Grady Little said afterwards.

Yanks skipper Joe Torre said he, “was very proud of my team. They certainly acted like a team.”

The antics began when Martinez threw the ball behind Garcia’s head with the scored tied 2-2, hitting him in the back.

The teams were warned as players from both sides jawed at each other.

Martinez, who has a history of throwing at opposing batters, pointed his finger at his head, perhaps signaling the Yankee players that he might throw at their heads.

Zimmer joined in with some remarks from the dugout.

In the bottom of the inning, with the Yankees now ahead, 4-2, Red Sox slugger Manny Ramirez charged the mound after he thought a pitch by Bomber hurler Roger Clemens was too close for comfort.

Ramirez, who grew up in Washington Heights, raised his bat and shouted expletives at Clemens.

Both benches cleared and Zimmer joined the fracas on the field.

The lovable, roly-poly Zimmer headed directly for Martinez, awkwardly lunging for the hurler.

Martinez sidestepped Zimmer, grabbed him by the head with both hands and tossed him to the ground like a rag doll.

“I was just trying to dodge him and push him away, and too bad his body fell,” Martinez insisted afterwards.

Zimmer, who has a metal plate in his head from a beaning in a 1953 game, returned to the dugout and had a bandage on his nose.

He quickly returned to his jovial self and was seen laughing later in the game.

There were no ejections – and play resumed after a 10-minute delay.

The Boston skipper later admitted Clemens’ pitch to Ramirez was nowhere near his head.

“I don’t think it was that close,” Little said.

Martinez’s sickening display had the Yanks and their fans crying foul.

“It’s unfortunate. The whole incident was unfortunate,” Yankee shortstop Derek Jeter said after the game.